Field of the Invention
The present disclosure relates to at least one image processing technique.
Description of the Related Art
A binarization process involves determining whether each pixel value of input color or gray scale image data is greater or less than a threshold value and converting the image data into a monochrome binary image. Japanese Patent Laid-Open No. 4-290177 describes a binarization process that is performed on pixels of image data by using a single threshold value.
In the binarization process described in Japanese Patent Laid-Open No. 4-290177, a shade component that may be included in image data depending on an image capture environment is not taken into consideration. When a shade component included in image data has a pixel value less than the threshold value, the shade component is converted into black by binarization. If a shaded document whose background is blank or white is captured as an image, a shaded white region is converted into black.